Which structure connects the throat to the middle ear?

The Eustachian tube is the correct answer because it serves as the vital passage that connects the throat (or pharynx) to the middle ear. Its primary function is to help equalize air pressure on both sides of the tympanic membrane (eardrum), which is essential for proper hearing and tympanic membrane function. The Eustachian tube opens during swallowing or yawning, allowing air to flow into the middle ear, helping to maintain the optimal pressure balance needed for sound transmission.

In contrast, other options do not serve this purpose: the tympanic membrane is the barrier separating the outer ear from the middle ear and does not connect to the throat; the auditory canal is the passage that leads to the tympanic membrane from the outer ear; and the external ear consists of the visible structures outside the head but does not connect to the throat at all.